Grid-Based Methods.
Grid-based methods avoid estimating raw depth values by predicting a BEV grid [1]}, [2]} representation, to be used as input for 3D detection architectures. Specifically, OFT [1]} populates a voxel grid by projecting voxels into the image plane and sampling image features, to be transformed into a BEV representation. Multiple voxels can be projected to the same image feature, leading to repeated features along the projection ray and reduced detection accuracy.
